You are examining the DNA sequences that code for the enzyme phosphofructokinase in skinks and Komodo dragons. You notice that the coding sequence that actually directs the sequence of amino acids in the enzyme is very similar in the two organisms but that the surrounding sequences vary quite a bit. What is the most likely explanation for this?
(a) Coding sequences are repaired more efficiently.
(b) Coding sequences are replicated more accurately.
(c) Coding sequences are packaged more tightly in the chromosomes to protect them from DNA damage.
(d) Mutations in coding sequences are more likely to be deleterious to the organism than mutations in noncoding sequences.
Answer: D